The invention relates to a self-propelled street cleaning machine adapted for cleaning relatively wide sections of pavement.
Street cleaning machines are known in the art, however, these machines, in general, utilize vacuum arrangements which are used to collect the dust which is swept by the brushes. One important problem with these machines is that they are relatively noisy due to the vacuum arrangement.
One can observe that the rubbish on streets having a relatively heavy flow of traffic collects at the edges thereof while the center of the street remains relatively clean. For this reason, the prior art machines are constructed to clean only relatively narrow widths, since only the side portions of the street have to be cleaned.
Also, with the current trend towards the use of pedestrian zones, street cleaning problems take on new dimensions. As the air current causing the rubbish to accumulate automatically in the afore described manner as a result of the passing vehicles is not existent in pedestrian zones, it is necessary to clean the entire pavement of a pedestrian zone. The prior art cleaning machines, because of their relatively narrow cleaning paths, are not adapted for large pedestrian zones. Further, pedestrian zones contain many obstacles, such as flower arrangements, goods displays and lighting facilities. If the pedestrian zones were cleaned with the conventional street cleaning machines more or less untouched areas, in particular corners and recesses, would remain.
The problem posed by the size of pedestrian zones could not be overcome simply by increasing the size of the street cleaning machine, since an increase in size would entail increase in the size of the vacuum arrangement which would, in turn, increase the noise. It would, on the other hand, be difficult to collect the rubbish without a vacuum.
It is therefore, an object of this invention to provide a street cleaning machine which is adapted for cleaning relatively wide sections of the pavement without causing undue amounts of noise. This object is accomplished in that a damp cloth or sack is arranged near the sweeping brushes. The sweeping brushes throw the dust against the damp sack where it collects and then falls in the form of scales. These scales are then swept by the sweeping brushes in the direction of a receptacle arrangement where they are then swept up, placed on a conveyor, and led to a container. The sweeping brushes are arranged in a twisted or spiral arrangement so that the scales will move along the revolving sweeping brushes in the proper direction, i.e. the direction of the receptacle arrangement. The cloth can be kept damp by carrying water somewhat like a wick, the cloth being attached to a liquid supply or preferably, the cloth can be a portion of a water permeable liquid container, e.g. a linen sack filled with water. The area of the machine which contains the cleaning apparatus is enclosed by skirts in order to prevent the undue distribution of dust. The dust is brushed against the damp cloth, collects there, and finally falls as scales which are collected by a receptacle arrangement.
It is another object of this invention to have a cleaning machine which is highly maneuverable and which can operate easily on a surface replete with obstacles.
It is another object of this invention to provide a machine which, although being capable of cleaning wide sections of pavement, is relatively narrow and can be kept in small garages as well as being capable of traveling down narrow paths. Other objects will become apparent in the following description.